This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our long term goals are to elucidate biopolymers molecular structures, especially polysaccharides, and their interactions with solvent and solute molecules and the synergistic interactions in mixed polysaccharides towards gaining insights about their structure-function relationships. In this regard, the main thrust of the current proposal is about determining the molecular architecture of a number of biologically important and industrially useful polysaccharides. Our ongoing study will include, the specimens from algal (iota, kappa and lambda carrageenans);bacterial (gellan analog and cepacian);fungal (glucuronoxylomannan);plant (rhamnogalacturonan);wood (galactoglucomannan) and a binary system (bacterial xanthan:plant glucomannan and bacterial acetan:plant glucomannan). More recently, we demonstrated that the polysaccharide fibers can be utilized as possible drug carriers (unpublished results). In this regard, our second aim would include producing polymeric cocrystals by complexing polysaccharides with small drug molecules, and determining their three-dimensional structures. Upon successful completion of the results would shed light about the polysaccharide:drug interactions towards developing controlled drug release carriers. These polysaccharides or polysaccharide complexes have an inherent tendency to form helical structures with only limited lateral ordering and are not amenable for growing single crystals. Hence, fiber diffraction is the only method of choice for visualizing their three-dimensional organization. Such structural information is essential towards understanding their interactions with solvent and solute molecules as well as with other polysaccharides for their effective utilization in food and pharmaceutical applications. The results will further highlight the conformational space available to polysaccharides as they occur in glycosaminoglycans and cellular walls.